10" Ball and Socket armature built by Wuchan Kim, a simple wire armature with tie downs in feet, contrasted with a 3" Stikfas toy.
Armatures are key ingredients in Stop Motion Animation. They are the skeleton of your puppet. Armatures can be extremely complicated costing thousands of dollars or extremely simple and put together in 15 minutes. I'll go over some of the differences now.
BALL AND SOCKET ARMATURES
Ball and Socket armatures are usually the best way to go when making a puppet. There are exceptions and I will get into them later. The B&S armature pictured above was built by Wuchan Kim. His type of armature is made in a modular way so the parts can be swapped out if needed. Because of this design, the animator will benefit from the swivel action that occurs naturally as well as the ball/socket movement. Wuchan also incorporates toe hinge joints into the feet. Email Wuchan if interested in purchasing a custom armature of this type. He does not sell kits, but will build a custom armature based on your design. There are more armature choices listed in RESOURCES.
On movies such as The Nightmare Before Christmas and Coraline, I've worked with some super complicated ball and socket armatures that have swivels built into the torso, arms and legs. They most always have hinge joints in the elbows, knees, and toes. These types of armatures must be custom machined and can costs thousands of dollars. Tom St. Amand and Merrick Cheney are 2 machinists who come to mind who have built this type of armature.
If you are planning to outfit your puppet with a Ball and Socket Armature, here are a few things to be mindful of:
Toe Joints are a must. Helpful especially when walking a puppet. Plan for toe joints and you will be a happy animator. Be sure to include threaded holes for tie-downs in both the foot and toe parts.
Ankle Joints. These, along with knees, can sometimes be the weakest part of the puppet, especially if your puppet is top-heavy. Make sure the ankle joints are strong enough to support your puppet on one leg, with the opposite leg outstretched but not touching the ground (as if about to land a step.) If it can't hold that pose, you will need better ankle joints or a support rig (you don't really want to resort to a rig if you can help it.)
Access. Make sure you are able to access the tensioning screw heads once the puppet is built. Slits can be pre-made and hid in the costume. If you're working with a big foam puppet, you may need to slice the foam, tension, re-glue and paint the seam. The best thing to do is plan for this ahead of time. Think of anything you can to simplify the tensioning process. Animators need to get in there to tension certain joints, especially ankles and knees it seems. This cannot really happen until the puppet is finished, only then can the armature by 'balanced' by careful tensioning of the joints.
Rig Points. K&S square tubing make great receptacles for removable rigs. Incorporate a tension screw and make sure it is accessible. Build the rig receptacle into the core of your puppet if you expect your character will be needing a rig (most do). You can also rig to the tie-downs in the feet but that is not optimal. Otherwise, you can go completely old school and suspend your puppet on fine wires using a Flying Rig.
The Wire Armature pictured above is about as simple as you can get. It's a 'one off' meaning, I made only one puppet for a single shot and if it broke during shooting, I would have a tough time fixing it. Wire will eventually break, that is a given, so it's best to be prepared ahead of time. Normally, the best way to build a good wire armature would be to make the parts easily replaceable. Aluminum wire limbs with K&S square stock that fit together are a good way to go. Incorporate rig points in the core as mentioned above if you intend to attach the puppet to a rig.
Here is a short SMA.com ID that I animated a few years ago with the same wire armature. I was lucky, he never broke. He was able to support his weight on one leg but I made his head too heavy, which made him a bit wobbly. It's best to make stop motion puppets as lightweight as possible.
Many Ball & Socket armatures use wire for fingers, hair, clothing. Sometimes wire is the best choice for the entire puppet. Most often, size will dictate this. I've animated rats, cats, small puppets completely made of wire. Sometimes joints are just too big. Other times, the design will dictate the best armature choice. While working on BUMP IN THE NIGHT for ABC Saturday TV, the puppet department went thru many different versions of the character Squishy, a jiggling mass of blue blobbiness. The first version of the puppet was completely made of clay. That didn't work, it was slow to animate and very limiting. Then a Ball and Socket armature was made for a foam body of Squishy. An improvement but too rigid. In the end, a simple wire armature gave the puppet the most range and flexibility with the foam latex skin.
this page is still a work in progress